Summary

This amendment adopts a new airworthiness directive (AD) that is applicable to International Aero Engines AG (IAE) V2500-A1 series turbofan engines. This action requires a one-time ultrasonic inspection of fan blade roots for cracks, and, if necessary, replacement of cracked fan blades with serviceable parts. This amendment is prompted by a report of dovetail root cracks visually detected on three fan blades from one engine during a routine inspection. The actions specified in this AD are intended to prevent fan blade root cracks, which could result in fan blade root failures, an uncontained engine failure, and damage to the aircraft.

Full text

SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to International Aero Engines AG (IAE) V2500-A1 series
turbofan engines. This action requires a one-time ultrasonic inspection
of fan blade roots for cracks, and, if necessary, replacement of
cracked fan blades with serviceable parts. This amendment is prompted
by a report of dovetail root cracks visually detected on three fan
blades from one engine during a routine inspection. The actions
specified in this AD are intended to prevent fan blade root cracks,
which could result in fan blade root failures, an uncontained engine
failure, and damage to the aircraft.
DATES: Effective October 21, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of October 21, 1998.
Comments for inclusion in the Rules Docket must be received on or
before December 7, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 98-ANE-63-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may also be sent
via the Internet using the following address: ``9-ad-
engineprop@faa.dot.gov''. Comments sent via the Internet must contain
the docket number in the subject line.
The service information referenced in this AD may be obtained from
Rolls-Royce Commercial Aero Engine Limited, P.O. Box 31, Derby,
England, DE2488J, Attention: Publication Services ICL-TP. This
information may be examined at the FAA, New England Region, Office of
the Regional Counsel, 12 New England Executive Park, Burlington, MA; or
at the Office of the Federal Register, 800 North Capitol Street, NW.,
suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Diane Cook, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-
7133, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: The Federal Aviation Administration (FAA)
has received reports of dovetail root cracks visually detected on three
fan blades from one engine during a routine turnaround inspection of an
Airbus A320 aircraft powered with International Aero Engines AG (IAE)
V2500-A1 turbofan engines. These cracks were located just inboard of
the fan blade root/disc abutment area and extend to the front face of
the blade root. Ultrasonic inspection of the other fan blades in this
engine revealed blade root cracks in every fan blade initiating in high cycle fatigue from multi
origins. Ultrasonic inspection of the fan disc from this engine also
revealed small cracks in eleven disc posts. The FAA has determined that
these fan blade root and fan disc post cracks were caused by an
undetermined event that induced extremely high stresses into the blade
roots and disc posts. A review of this engine history has not isolated
any event other than a fan case acoustic panel loss six months prior to
this routine inspection. However, other in-service V2500-A1 and -A5
engines that experienced a fan case acoustic panel loss have completed
the ultrasonic inspections without finding a fan blade root crack. As
the investigation continues, IAE has recommended that the V2500-A1
engine fleet ultrasonic inspect the fan blades. Approximately 95% of
the V2500-A1 engine fleet have completed this fan blade ultrasonic
inspection without finding fan blade root cracks. This condition, if
not corrected, could result in fan blade root cracks, which could
result in fan blade root failure, an uncontained engine failure, and
damage to the aircraft.
The FAA has reviewed and approved the technical contents of IAE
Service Bulletin (SB) No. V2500-ENG-72-0316, Revision 2, dated August
28, 1998, that describes procedures for ultrasonic inspection of fan
blade roots for cracks.
Since an unsafe condition has been identified that is likely to
exist or develop on other engines of the same type design, this AD is
being issued to prevent fan blade root cracks. This AD requires a one-
time ultrasonic inspection of fan blade roots for cracks, and, if
necessary, replacement of cracked fan blades with serviceable parts.
The actions are required to be accomplished in accordance with the SB
described previously.
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this rule by
submitting such written data, views, or arguments as they may desire.
Communications should identify the Rules Docket number and be submitted
in triplicate to the address specified under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the rule. All comments submitted will be
available, both before and after the closing date for comments, in the
Rules Docket for examination by interested persons. A report that
summarizes each FAA-public contact concerned with the substance of this
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 98-ANE-63-AD.'' The postcard will be date stamped and
returned to the commenter.
The regulations adopted herein will not have substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government. Therefore, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and is not a ``significant regulatory action''
under Executive Order 12866.
It has been determined further that this action involves an
emergency regulation under DOT Regulatory Policies and Procedures (44
FR 11034, February 26, 1979). If it is determined that this emergency
regulation otherwise would be significant under DOT Regulatory Policies
and Procedures, a final regulatory evaluation will be prepared and
placed in the Rules Docket. A copy of it, if filed, may be obtained
from the Rules Docket at the location provided under the caption
ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends part 39 of
the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
98-21-01 International Aero Engines AG: Amendment 39-10809. Docket
98-ANE-63-AD.
Applicability: International Aero Engines AG (IAE) V2500-A1
series turbofan engines, installed on but not limited to Airbus A320
series aircraft.
Note 1: This airworthiness directive (AD) applies to each engine
identified in the preceding applicability provision, regardless of
whether it has been modified, altered, or repaired in the area
subject to the requirements of this AD. For engines that have been
modified, altered, or repaired so that the performance of the
requirements of this AD is affected, the owner/operator must request
approval for an alternative method of compliance in accordance with
paragraph (b) of this AD. The request should include an assessment
of the effect of the modification, alteration, or repair on the
unsafe condition addressed by this AD; and, if the unsafe condition
has not been eliminated, the request should include specific
proposed actions to address it.
Compliance: Required as indicated, unless accomplished
previously.
To prevent fan blade root cracks, which could result in fan
blade root failure, an uncontained engine failure, and damage to the
aircraft, for those engines that have not previously been inspected
in accordance with IAE Service Bulletin (SB) No. V2500-ENG-72-0316,
dated May 15, 1998; or No. V2500-ENG-72-0316, Revision 1, dated June
5, 1998; or No.V2500-ENG-72-0316, Revision 2, dated August 28, 1998,
accomplish the following:
(a) Within 150 hours time in service (TIS) after the effective
date of this AD, perform a one-time ultrasonic inspection of fan
blade roots for cracks, and, if necessary, replace cracked fan
blades with serviceable parts, in accordance with IAE Service
Bulletin (SB) No. V2500-ENG-72-0316, Revision 2, dated August 28,
1998.
(b) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office.
Operators shall submit their requests through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, Engine Certification Office.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office.
(c) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the aircraft to a location where
the inspection requirements of this AD can be accomplished.
(d) The actions required by this AD shall be done in accordance
with the following IAE SB:
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Document No. Pages Revision Date
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V2500-ENG-72-0316............................... 1-7 2 August 28, 1998.
Total pages: 7.
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This incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from Rolls-Royce Commercial Aero Engine
Limited, P.O. Box 31, Derby, England, DE2488J, Attention:
Publication Services ICL-TP. Copies may be inspected at the FAA, New
England Region, Office of the Regional Counsel, 12 New England
Executive Park, Burlington, MA; or at the Office of the Federal
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(e) This amendment becomes effective on October 21, 1998.
Issued in Burlington, Massachusetts, on September 28, 1998.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 98-26529 Filed 10-5-98; 8:45 am]
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